Growth of the skull of the bottlenose dolphin, Tursiops truncatus, in the Southwest Atlantic Ocean

Authors

  • André Silva Barreto Laboratório de Informática da Biodiversidade e Geomática, Centro de Ciências Tecnológicas da Terra e do Mar - CTTMar, Universidade do Vale do Itajaí - UNIVALI

DOI:

https://doi.org/10.5597/00229

Keywords:

Tursiops truncatus, age, growth, maturity

Abstract

Defining the age of attainment of physical maturity is important for many studies, including identification of stocks, populations or species. In order to identify the age when the skull of the bottlenose dolphin, Tursiops truncatus, reaches maturity, skulls of fifty-three specimens found stranded along the coasts of southern Brazil, Uruguay and northern Argentina (27o35’S, 48o34’W-36o49’S, 55o19’W) were analyzed. Sixty skull measurements were taken to compare the growth rate of the different functional apparatuses. Age was estimated by counts of growth layer groups in the dentine of decalcified, stained longitudinal sections of teeth. Von Bertalanffy’s equation was applied to assess the growth and determine the age at maturity of each apparatus. Generally the maturation of skull starts at age two and stabilizes at age five, and the age of reaching the mature size varies amongst different characters. The braincase is the most precocious apparatus, while the feeding is the one that last stabilizes. The development patterns observed for the hearing, vision and breathing apparatuses were similar. Statistic analysis revealed significant differences among the ages at maturity, but not for von Bertalanffy’s growth equation parameters for each functional apparatus. For the studied population it is suggested that skulls can be considered mature in animals with more than
five years. 

References

Au, W.W.L. (2008) Echolocation. Pages 348-357 in Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds) Encyclopedia of marine mammals. Academic Press, San Diego, CA, USA.

Barreto, A.S. (2000) Variação craniana e genética de Tursiops truncatus (Delphinidae, Cetacea) na costa Atlântica da América do Sul. Ph.D. Thesis. Universidade do Rio Grande. Rio Grande, RS, Brazil. 123 pp.

Barreto, A.S. and Rosas, F.C.W. (2006) Comparative growth analysis of two populations of Pontoporia blainvillei on the Brazilian Coast. Marine Mammal Science 22: 644-653. http://dx.doi.org/10.1111/j.1748-7692.2006.00040.x

Barros, N.B. and Odell, D.K. (1990) Food habits of bottlenose dolphins in the Southeastern United States. Pages 309-328 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Borobia, M. (1989) Distribution and morphometrics of South American dolphins of the genus Sotalia. M.Sc. Thesis. McGill University. Montreal, Quebec, Canada. 81 pp.

Changizi, M.A. (2003) Relationship between number of muscles, behavioral repertoire size, and encephalization in mammals. Journal of Theoretical Biology 220: 157–168. http://dx.doi.org/10.1006/jtbi.2003.3125

Charlton-Robb, K., Gershwin, L., Thompson, R., Austin, J., Owen, K. and McKechnie, S. (2011) A new dolphin species, the Burrunan dolphin Tursiops australis sp. nov., endemic to southern Australian coastal waters. PLoS ONE 6(9): e24047. http://dx.doi.org/10.1371/journal.pone.0024047

Chen, I., Chou, L.S., Chen, Y.J. and Watson, A. (2011) The maturation of skulls in postnatal Risso’s dolphins (Grampus griseus) from Taiwanese waters. Taiwania 56: 177-185.

Cockcroft, V.G. and Ross, G.J. (1990a) Age, growth, and reproduction of bottlenose dolphins Tursiops truncatus from the east coast of Southern Africa. Fishery Bulletin 88(2): 289-302.

Cockcroft, V.G. and Ross, G.J. (1990b) Observations of the early development of a captive bottlenose dolphin calf. Pages 461-478 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Cockcroft, V.G. and Ross, G.J. (1990c) Food and feeding of the Indian Ocean bottlenose dolphin off Southern Natal, South Africa. Pages 295-308 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Dailey, M.D. and Perrin, W.F. (1973) Helminth parasites of porpoises of the genus Stenella in the eastern tropical Pacific, with descriptions of two new species: Mastigonema stenellae gen. et sp. n. (Nematoda: Spiruroidea) and Zalophotrema pacificum sp. n. (Trematoda: Digenea). Fishery Bulletin 71: 455-471.

Fernandez, S. and Hohn, A.A. (1998) Age, growth and calving season of bottlenose dolphins, Tursiops truncatus, off coastal Texas. Fishery Bulletin 96(2): 357-365.

Gao, A., Zhou, K. and Wang, Y. (1995) Geographical variation in morphology of bottlenose dolphins (Tursiops sp.) in Chinese waters. Aquatic Mammals 21(2): 121-135.

Gaskin, D.E. (1982) The ecology of whales and dolphins. Heinemann, London, UK.

Hersh, S.L. and Duffield, D.A. (1990) Distinction between Northwest Atlantic offshore and coastal bottlenose dolphins based on hemoglobin profile and morphometry. Pages 129-139 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Hersh, S.L., Odell, D.K. and Asper, E.D. (1990) Sexual dimorphism in bottlenose dolphins from the east coast of Florida. Marine Mammal Science 6(4): 305-315. http://dx.doi.org/10.1111/j.1748-7692.1990.tb00360.x

Hohn, A.A. (1980) Age determination and age related factors in the teeth of western North Atlantic bottlenose dolphins. Scientific Reports of the Whales Research Institute 32: 39-66.

Hohn, A.A., Scott, M.D., Wells, R.S., Sweeney, J.C. and Irvine, A.B. (1989) Growth layers in teeth from known-age, free ranging bottlenose dolphins. Marine Mammal Science 5(4): 315-342. http://dx.doi.org/10.1111/j.1748-7692.1989.tb00346.x

Lodi, L., Domit, C., Laporta, P., Di Tullio, J.C., Martins, C.C.A. and Vermeulen, E. (2016) Report of the Working Group on the Distribution of Tursiops truncatusin the Southwest Atlantic Ocean. Latin American Journal of Aquatic Mammals 11(1-2): 29-46. http://dx.doi.org/10.5597/lajam00214

Marino, L. (2004) Cetacean brain evolution: multiplication generates complexity. International Journal of Comparative Psychology 17: 1-16.

Mattson, M.C., Mullin, K.D., Ingram, G.W. and Hoggard, W. (2006) Age structure and growth of the bottlenose dolphin (Tursiops truncatus) from strandings in the Mississippi Sound region of the north-central Gulf of Mexico from 1986 to 2003.Marine Mammal Science 22(3): 654–666. http://dx.doi.org/10.1111/j.1748-7692.2006.00057.x

McFee, W.E., Schwacke, J.H., Stolen, M.K., Mullin, K.D. and Schwacke, L.H. (2010) Investigation of growth phases for bottlenose dolphins using a Bayesian modeling approach. Marine Mammal Science 26(1): 67-85. http://dx.doi.org/1010.1111/j.1748-7692.2009.00306.x

Mead, J.G. and Potter, C.W. (1990) Natural history of bottlenose dolphins along the central Atlantic coast of the United States. Pages 165-195 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Mead, J.G. and Potter, C.W. (1995) Recognizing two populations of the bottlenose dolphin (Tursiops truncatus) off the Atlantic coast of North America morphologic and ecologic considerations .IBI Reports (International Marine Biological Research Institute (Kamogawa, Japan) 5: 31-44.

Mead, J.G. and Fordyce, R.E. (2009) The therian skull: a lexicon with emphasis on the odontocetes. Smithsonian Contributions to Zoology 627: 1-248.

Oelschläger, H.H.A. and Oelschläger, J.S. (2008) Brain. Pages 134-149 in Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds) Encyclopedia of marine mammals. Academic Press, San Diego, CA, USA.

Ott, P.H., Barreto, A.S., Siciliano, S., Laporta, P., Domit, C., Fruet, P., Dalla Rosa, L., Santos, M.C.O., Meirelles, A.C., Marchesi, M.C., Botta, S., Oliveira, L.R., Moreno, I.B., Wickert, J., Vermeulen, E., Hoffmann, L.S., Baracho, C. and Simões Lopes, P.C. (2016) Report of the Working Group on Taxonomy and Stock Identity of bottlenose dolphins in the Southwest

Atlantic Ocean.Latin American Journal of Aquatic Mammals 11(1-2): 16-28. http://dx.doi.org/10.5597/lajam00213

Perrin, W.F. (1975) Variation of spotted and spinner porpoise (genus Stenella) in the eastern Tropical Pacific and Hawaii. Bulletin of the Scripps Institute of Oceanography 21: 1-206.

Perrin, W.F. and Heyning, J.E. (1993) Rostral fusion as a criterion of cranial maturity in the common dolphin, Delphinus delphis. Marine Mammal Science 9(2): 195–197. http://dx.doi.org/10.1111/j.1748-7692.1993.tb00444.x

Perrin, W.F. and Myrick, A.C., Eds (1980) Age determination of toothed whales and sirenians. Report of the International Whaling Commission Special Issue 3. Cambridge, UK. 229 pp.

Pinedo, M.C. (1982) Análise dos conteúdos estomacais de Pontoporia blainvillei (Gervais & D’Orbigny, 1844) e Tursiops gephyreus (Lahille, 1908) (Cetacea, Platanistidae e Delphinidae) na zona estuarial e costeira de Rio Grande, RS, Brasil. M.Sc. Thesis. Universidade do Rio Grande. Rio

Grande, Rio Grande do Sul, Brazil. 95 pp.

Pinedo, M.C. (1991) Development and variation of the Franciscana, Pontoporia blainvillei. Ph.D. Thesis. University of California. Santa Cruz, CA, USA. 406 pp.

Ridgway, S.H. (1990) The central nervous system of the bottlenose dolphin. Pages 69-97 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Rommel, S. (1990) Osteology of the bottlenose dolphin. Pages 101-128 in Leatherwood, S. and Reeves, R.R. (Eds) The bottlenose dolphin. Academic Press, San Diego, CA, USA.

Ross, G.J.B. (1977) The taxonomy of bottlenosed dolphins Tursiops species in South African waters, with notes on their biology. Annals of the Cape Provincial Museums (Natural History) 11: 135-194.

Schmiegelow, J.M.M. (1990) Estudo sobre cetáceos odontocetes

encontrados em praias da região entre Iguape (SP) e Baía de

Paranaguá (PR) (24o42’S-25o28’S) com especial referência a Sotalia fluviatilis (Gervais, 1853) (Delphinidae). M.Sc. Thesis. Universidade de São Paulo. São Paulo, Brazil. 149 pp.

Schnute, J. (1981) A versatile growth model with statistically stable parameters. Canadian Journal of Fisheries and Aquatic Sciences 38: 1128-1140. http://dx.doi.org/10.1139/f81-153

Siciliano, S., Ramos, R.M.A., Di Beneditto, A.P.M., Santos, M.C.O., Fragoso, A.B., Brito, J.L., Azevedo, A.F., Vicente, A.F.C., Zampirolli, E., Alvarenga, F.S., Barbosa, L. and Lima, N.R.W. (2007) Age and growth of some delphinids in southeastern Brazil. Journal of the Marine Biological Association of the United Kingdom 87: 293-303. http://dx.doi.org/10.1017/S0025315407053398

StatSoft Inc. (1998) STATISTICA for Windows user’s guide. Release 5.1. StatSoft Inc. Tulsa, OK, USA.

Turner, J.P and Worthy, G.A.J. (2003) Skull morphometry of bottlenose dolphins (Tursiops truncatus) from the Gulf of Mexico. Journal of Mammalogy 84(2): 665-672. http://dx.doi.org/10.1644/1545-1542(2003)084<0665:smobdt>2.0.co;2

Van Waerebeek, K. (1993) Geographic variation and sexual dimorphism in the skull of the dusky dolphin, Lagenorhynchus obscurus (Gray, 1828). Fishery Bulletin 91(4): 754-774.

Wang, J.Y., Chou, L-S. and White, B.N. (2000) Osteological differences between two sympatric forms of bottlenose dolphins (genus Tursiops) in Chinese waters. Journal of Zoology 252(2): 147-162.

http://dx.doi.org/10.1111/j.1469-7998.2000.tb00611.x

Worthy, G.A.J. and Hickie, J.P. (1986) Relative brain size in marine mammals. The American Naturalist 128(4): 445-459.

Zerbini, A.N., Secchi, E.R., Bassoi, M., Dalla-Rosa, L., Higa, A., Sousa, L., Moreno, I.B., Möller, L. and Caon, G. (2004) Distribuição e abundância relativa de cetáceos na Zona Econômica Exclusiva na Região Sudeste-Sul do Brasil. Revizee-Score Sul. Instituto Oceanográfico, Universidade

de São Paulo Série Documentos REVIZEE-Score Sul. 40 pp. http://www.mma.gov.br/estruturas/revizee/_arquivos/revizee_cetaceos.pdf

Downloads

Published

2017-01-08

How to Cite

Barreto, A. S. (2017). Growth of the skull of the bottlenose dolphin, Tursiops truncatus, in the Southwest Atlantic Ocean. Latin American Journal of Aquatic Mammals, 11(1-2), 199-211. https://doi.org/10.5597/00229

Issue

Section

Articles